Benefits Administrator

Matrix Finance and Accounting; Mercer Island (WA); On-site; USD 65,000 - 90,000; Full time

Job summary

Matrix Finance and Accounting on Mercer Island, WA, seeks a Benefits Administrator to manage day-to-day employee benefits programs including medical, dental, vision, FSA/HSA, Section 125, and 401(k) plans. You will coordinate enrollments, answer questions, and ensure accurate data flows between HRIS, payroll, and carriers.

Responsibilities include managing workers' compensation files, auditing benefit data, and providing backup payroll support while delivering confidential HR support across the

Qualifications

• Two years of benefits administration experience including medical/dental/vision and at least one of FSA/HSA/Section 125 or 401(k) plans.
• Familiarity with ERISA, ACA, COBRA, HIPAA and benefit practices.
• Strong attention to detail and ability to manage high-volume enrollments.

Responsibilities

• Administer medical, dental, vision, FSA/HSA, Section 125 and 401(k) plans in line with documents and laws.
• Coordinate enrollments, life events, terminations, and eligibility with accuracy.
• Serve as primary benefits resource for questions and plan comparisons; escalate issues as needed.
• Maintain benefit records in HRIS and carrier portals; audit eligibility and deductions.
• Prepare benefits communications and notices; support retirement plan administration.

Skills

Benefits administration

ERISA/ACA knowledge

Attention to detail

HRIS proficiency

Excel

Carrier portals

Education

Bachelor's or Associate degree in HR or related field

Tools

HRIS

Microsoft Excel

Carrier portals

Job description

The Benefits Administrator is responsible for the day-to-day administration of employee benefits programs, including medical, dental, vision, supplemental/voluntary products, the Section 125 cafeteria plan, Flexible Spending Accounts (FSA), Health Savings Accounts (HSA), and 401(k)/retirement plans. This role manages workers' compensation claims from first report through return to work or closure, audits benefits data feeds between the HRIS/payroll system and insurance carriers, coordinates enrollments and qualifying life events, and serves as the primary point of contact for employee benefits questions. The position also provides backup payroll support on a periodic basis and general Human Resources support across the organization.

Essential Duties and Responsibilities

Benefits Administration

• Administer medical, dental, vision, supplemental/voluntary, Section 125, FSA, HSA, and 401(k) plans in accordance with plan documents, carrier contracts, and applicable federal and state law, including ERISA, ACA, COBRA, and HIPAA.
• Coordinate new-hire, open enrollment, qualifying life event, and termination enrollments and elections; ensure timely and accurate processing of coverage start and stop dates.
• Serve as the primary employee resource for benefits questions, plan comparisons, eligibility, coverage issues, claims escalation, and retirement plan enrollment or contribution questions; elevate carrier and plan-design issues to the HR Manager.
• Maintain accurate employee benefit records in the HRIS and carrier portals; audit employee accounts for eligibility, dependent documentation, coverage elections, premium deductions, and contribution rates.
• Administer the Section 125 cafeteria plan, including pre-tax premium elections, FSA and HSA enrollments, contribution changes, annual IRS contribution limits, and mid-year election changes permitted by qualifying events; coordinate with the FSA/HSA vendor and confirm payroll deductions and employer contributions match employee elections.
• Prepare and distribute benefits communications, enrollment materials, summaries of benefits and coverage (SBCs), and required notices in partnership with the HR Manager.
• Support retirement plan administration, including eligibility tracking, enrollment and auto-enrollment coordination, contribution changes, catch-up contributions, and liaison with the recordkeeper.
• Coordinate COBRA qualifying event notices and administration with the COBRA administrator; track qualifying events and confirm timely notification.
• Assist with annual open enrollment planning, employee education sessions, and post-enrollment reconciliation.
• Coordinate with payroll on premium deductions, arrears, FSA/HSA deductions, and retirement contribution remittance so elections match pay-cycle deductions.

Data Feed Management & Audit

• Monitor, review, and audit data feeds (EDI or similar) between the HRIS/payroll system and medical, dental, vision, supplemental, FSA/HSA, and retirement plan carriers/vendors to confirm enrollments, terminations, demographic changes, and coverage levels transmitted correctly.
• Identify, research, and resolve feed errors, rejected records, missing dependents, mismatched effective dates, and premium/eligibility discrepancies with carriers and vendor support.
• Maintain audit logs and documentation of feed exceptions, corrections, and follow-up until resolved.
• Perform monthly reconciliation of carrier invoices against payroll deductions and employee elections; elevate unresolved variances to the HR Manager.
• Partner with HRIS implementation/support and the HR Manager to validate mappings, plan codes, and ongoing feed integrity.

Workers' Compensation Claims

• Manage workers' compensation claims from first report of injury through claim closure, including coordination with injured employees, site/department leadership, medical providers, claims administrators or adjusters, and vocational and return-to-work resources.
• Ensure timely and accurate filing of employer reports of injury and required follow-up documentation; track claim status, time loss, light duty, and restrictions.
• Maintain complete claim files and an audit-ready trail of communications, medical notes received, work status reports, wage information, and accommodation and return-to-work efforts.
• Coordinate stay-at-work, return-to-work, and light-duty assignments with site leadership consistent with medical restrictions and operational needs; document all offers of modified duty.
• Partner with payroll on time-loss wage reporting and related wage information requests; flag premium or experience-rating issues for the HR Manager.
• Monitor claim activity for patterns, delayed reporting, or compliance risk and elevate concerns to the HR Manager; support audits, protests, and appeals as needed.
• Communicate professionally and factually with employees about the claim process, work status, and next steps without providing legal or medical advice.

Payroll Support

• Serve as backup payroll support, assisting with payroll processing on a periodic basis and during scheduled coverage periods.
• Confirm new-hire, status-change, and termination records reflect accurate benefit eligibility dates and benefit deductions.
• Respond to employee pay and deduction inquiries during payroll coverage periods; elevate wage-and-hour or classification issues to the HR Manager.

General Human Resources Support

• Assist with general HR tasks such as onboarding support, personnel file maintenance, employment verifications, leave tracking coordination (including FMLA/leave-of-absence documentation handoff), and employee inquiries referred by site leadership.
• Support HR projects, policy updates, audits, and compliance requests assigned by the HR Manager.
• Maintain confidentiality of employee health, benefits, and personnel information at all times.
• Perform other related duties as assigned.

Qualifications

Required

• High school diploma or equivalent required; associate or bachelor's degree in Human Resources, Business Administration, or a related field preferred.
• Minimum of two (2) years of benefits administration experience covering medical, dental, vision, and at least one of supplemental products, Section 125/FSA/HSA, or 401(k)/retirement plans.
• Demonstrated experience auditing carrier invoices and/or eligibility files; familiarity with EDI or HRIS-to-carrier data feeds strongly preferred.
• Working knowledge of ERISA, ACA, COBRA, HIPAA, Section 125, and standard group benefits practices.
• Strong attention to detail, organizational skills, and ability to manage high-volume, deadline-driven enrollment and audit work.
• Excellent written and verbal communication skills; ability to explain benefits clearly and professionally to employees at all levels.
• Proficiency with HRIS/payroll systems, Microsoft Excel, and carrier/vendor portals. Ability to research pay and deduction issues and document corrections.
• Ability to handle confidential information with discretion and professionalism.