UPDATE 2-U.S. Obamacare 2018 exchange enrollment drops 3 pct -CMS

(Adds year-earlier figure for consumers with tax credits)

April 3 (Reuters) - About 11.8 million consumers nationwide enrolled in 2018 Obamacare exchange plans, a 3 percent drop from last year when 12.2 million consumers signed up, according to a final government tally released on Tuesday by the Centers for Medicare and Medicaid Services.

The tally includes both sign-ups on the exchange run by the federal government for 39 states, which was released on a provisional basis late in 2017, and on the 12 other exchanges run by Washington, D.C. and the remaining states.

CMS said the average premium before tax credits in 2018 is $621 a month, an increase of more than 30 percent from last year.

However, those receiving tax credits - around 83 percent of consumers on Obamacare - will pay around $89 a month on average in premiums, the agency said. That is down 16 percent from $106 a month last year.

Private insurers sell strictly regulated individual insurance plans through the Obamacare online exchanges that the government subsidizes based on a person's income.

U.S. President Donald Trump in October cut off billions of dollars in subsidy payments to insurers that help people pay for medical costs, causing insurers to raise 2018 premiums or drop out of selling plans in the Obamacare marketplace.

His administration also halved the enrollment period to six weeks and cut the federal advertising and outreach budget by 90 percent. It also has proposed putting cheaper insurance policies offering bare-bones medical coverage on the Obamacare market in 2019 or 2020. (Reporting by Michael Erman and Caroline Humer in New York; editing by Matthew Lewis and Lisa Shumaker)