The Massachusetts Health Connector is extending the deadline to complete an application and pick a health plan until Feb. 23.
The deadline had been Feb. 15, but officials pushed it back a week because heavy snowstorms have made it hard for some people to sign up for insurance.
Officials say the extreme weather also led to a number of days this month when the call center was short-staffed, leading to long wait times.
The extension gives applicants an additional week to complete an application, find out if they qualify for MassHealth or Health Connector coverage, select a plan and make a payment.
The Feb. 23 deadline for making a payment stays in place.
As of Wednesday, about 343,000 had enrolled in coverage, including 240,000 automatically enrolled in MassHealth.