Maine’s Amy Allen is starting out the new year on top.

Allen co-wrote the song “Without Me” by Halsey, which has reached No. 1 on Billboard’s Hot 100 pop music chart, the music magazine reported Monday.

It’s Allen’s first No. 1, not bad considering she’s only been writing pop songs full time for less than two years.

“I was through-the-roof excited when I found out about it,” Allen, 26, said Tuesday from Los Angeles. “I really couldn’t ask for any more than this.”

While Allen’s new year is starting out with a bang, 2018 wasn’t bad either. She co-wrote the radio hit “Back to You” by Selena Gomez, which was released in May and peaked at No. 18 on the Hot 100 chart in November. Both songs have gotten a ton of radio airplay on pop stations around the country.

Allen also co-wrote a song called “When You’re Ready” on Shawn Mendes’ self-titled album. The album is nominated for a Grammy – awards will be given out Feb. 10 – in the pop vocal album category.

But Allen says she won’t attend the Grammy Awards this year because she’s traveling to writing sessions with other artists. She said other songs she’s co-written are scheduled to be released in January, February and March, but she can’t talk about them yet.

Allen co-wrote “Without You” with Halsey (whose real name is Ashley Nicolette Frangipane) and another singer-songwriter, Delacey (whose real name is Brittany Amaradio).

Because she co-writes songs with artists and other writers, Allen declined to say which parts of the songs she contributes. She’s been busy in Los Angeles over the past year, often booking two writing sessions a day.

Billboard’s rankings are based on sales, airplay and streaming. “Without Me” will officially become the most popular tune in the land on Saturday, since Billboard’s rankings are released weekly. The song has been on the Billboard Hot 100 chart for 13 weeks.

The song is Halsey’s second successful collaboration with a Mainer. She sang with Freeport’s Drew Taggart of The Chainsmokers on the No. 1 Billboard hit “Closer” in 2016.

Allen grew up in Windham and graduated from Waynflete School in Portland. While still in high school, she recorded a studio album of her own music, and while in college, she spent six weeks as a contestant on the NBC singing competition “The Voice.”

She attended Berklee College of Music in Boston, where she took a songwriting class taught by Kara DioGuardi, a former “American Idol” judge and successful pop songwriter who lives in York.

While in Boston, Allen formed a band, Amy & The Engine, which performed her original songs around the region and the country. Her songs got noticed by publishing companies and eventually led to her becoming a full-time songwriter in Los Angeles.

Comments are not available on this story.